This application claims the priority of Korean Patent Application No. 2003-97149, filed on Dec. 26, 2003, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to an apparatus and method for computing a value of a hash function allowing compression of a message to increase the efficiency of digital signing that guarantees authentication and integrity of important information.
2. Description of the Related Art
Secure Hash Algorithms (SHAs) are algorithms developed by the National Institute of Standards and Technology (NIST), defined in the Federal Information Processing Standard (FIPS) 180-1. SHA-1, which is a type of SHA, divides an incoming message into units of 512-bit blocks using separation or zero padding, performs a rounding operation on the 512-bit blocks 80 times, and outputs a 160-bit compressed message. In particular, the SHA-1 hash algorithm generates a digital signature for the compressed message, thereby reducing the time required for digital signing.
The SHA is mainly used to increase the efficiency of digital signing. Thus, it is important to perform the algorithm quickly and reduce the size of an algorithm processor to minimize the load on a system due to addition of the processor. Most of the existing SHAs are embodied as software. Therefore, there is a growing need for development of an SHA-1 processor (or an SHA-1 hash operation unit) that can process data faster than SHAs embodied as software and serve power saving and safety of data.